[PATCH v2] mm, slab: don't wrap internal functions with alloc_hooks()
From: Vlastimil Babka
Date: Mon May 27 2024 - 05:01:53 EST
The functions __kmalloc_noprof(), kmalloc_large_noprof(),
kmalloc_trace_noprof() and their _node variants are all internal to the
implementations of kmalloc_noprof() and kmalloc_node_noprof() and are
only declared in the "public" slab.h and exported so that those
implementations can be static inline and distinguish the build-time
constant size variants. The only other users for some of the internal
functions are slub_kunit and fortify_kunit tests which make very
short-lived allocations.
Therefore we can stop wrapping them with the alloc_hooks() macro.
Instead add a __ prefix to all of them and a comment documenting these
as internal. Also rename __kmalloc_trace() to __kmalloc_cache() which is
more descriptive - it is a variant of __kmalloc() where the exact
kmalloc cache has been already determined.
The usage in fortify_kunit can be removed completely, as the internal
functions should be tested already through kmalloc() tests in the
test variant that passes non-constant allocation size.
Reported-by: Kent Overstreet <kent.overstreet@xxxxxxxxx>
Cc: Suren Baghdasaryan <surenb@xxxxxxxxxx>
Cc: Kees Cook <keescook@xxxxxxxxxxxx>
Signed-off-by: Vlastimil Babka <vbabka@xxxxxxx>
---
v2: keep _noprof per Kent, remove usage from fortify_kunit per Kees
include/linux/slab.h | 48 ++++++++++++++++++++++----------------------
lib/fortify_kunit.c | 5 -----
lib/slub_kunit.c | 2 +-
mm/slub.c | 26 ++++++++++++------------
4 files changed, 38 insertions(+), 43 deletions(-)
diff --git a/include/linux/slab.h b/include/linux/slab.h
index 7247e217e21b..ed6bee5ec2b6 100644
--- a/include/linux/slab.h
+++ b/include/linux/slab.h
@@ -528,9 +528,6 @@ static_assert(PAGE_SHIFT <= 20);
#include <linux/alloc_tag.h>
-void *__kmalloc_noprof(size_t size, gfp_t flags) __assume_kmalloc_alignment __alloc_size(1);
-#define __kmalloc(...) alloc_hooks(__kmalloc_noprof(__VA_ARGS__))
-
/**
* kmem_cache_alloc - Allocate an object
* @cachep: The cache to allocate from.
@@ -568,31 +565,34 @@ static __always_inline void kfree_bulk(size_t size, void **p)
kmem_cache_free_bulk(NULL, size, p);
}
-void *__kmalloc_node_noprof(size_t size, gfp_t flags, int node) __assume_kmalloc_alignment
- __alloc_size(1);
-#define __kmalloc_node(...) alloc_hooks(__kmalloc_node_noprof(__VA_ARGS__))
-
void *kmem_cache_alloc_node_noprof(struct kmem_cache *s, gfp_t flags,
int node) __assume_slab_alignment __malloc;
#define kmem_cache_alloc_node(...) alloc_hooks(kmem_cache_alloc_node_noprof(__VA_ARGS__))
-void *kmalloc_trace_noprof(struct kmem_cache *s, gfp_t flags, size_t size)
- __assume_kmalloc_alignment __alloc_size(3);
+/*
+ * The following functions are not to be used directly and are intended only
+ * for internal use from kmalloc() and kmalloc_node()
+ * with the exception of kunit tests
+ */
+
+void *__kmalloc_noprof(size_t size, gfp_t flags)
+ __assume_kmalloc_alignment __alloc_size(1);
+
+void *__kmalloc_node_noprof(size_t size, gfp_t flags, int node)
+ __assume_kmalloc_alignment __alloc_size(1);
-void *kmalloc_node_trace_noprof(struct kmem_cache *s, gfp_t gfpflags,
- int node, size_t size) __assume_kmalloc_alignment
- __alloc_size(4);
-#define kmalloc_trace(...) alloc_hooks(kmalloc_trace_noprof(__VA_ARGS__))
+void *__kmalloc_cache_noprof(struct kmem_cache *s, gfp_t flags, size_t size)
+ __assume_kmalloc_alignment __alloc_size(3);
-#define kmalloc_node_trace(...) alloc_hooks(kmalloc_node_trace_noprof(__VA_ARGS__))
+void *__kmalloc_cache_node_noprof(struct kmem_cache *s, gfp_t gfpflags,
+ int node, size_t size)
+ __assume_kmalloc_alignment __alloc_size(4);
-void *kmalloc_large_noprof(size_t size, gfp_t flags) __assume_page_alignment
- __alloc_size(1);
-#define kmalloc_large(...) alloc_hooks(kmalloc_large_noprof(__VA_ARGS__))
+void *__kmalloc_large_noprof(size_t size, gfp_t flags)
+ __assume_page_alignment __alloc_size(1);
-void *kmalloc_large_node_noprof(size_t size, gfp_t flags, int node) __assume_page_alignment
- __alloc_size(1);
-#define kmalloc_large_node(...) alloc_hooks(kmalloc_large_node_noprof(__VA_ARGS__))
+void *__kmalloc_large_node_noprof(size_t size, gfp_t flags, int node)
+ __assume_page_alignment __alloc_size(1);
/**
* kmalloc - allocate kernel memory
@@ -654,10 +654,10 @@ static __always_inline __alloc_size(1) void *kmalloc_noprof(size_t size, gfp_t f
unsigned int index;
if (size > KMALLOC_MAX_CACHE_SIZE)
- return kmalloc_large_noprof(size, flags);
+ return __kmalloc_large_noprof(size, flags);
index = kmalloc_index(size);
- return kmalloc_trace_noprof(
+ return __kmalloc_cache_noprof(
kmalloc_caches[kmalloc_type(flags, _RET_IP_)][index],
flags, size);
}
@@ -671,10 +671,10 @@ static __always_inline __alloc_size(1) void *kmalloc_node_noprof(size_t size, gf
unsigned int index;
if (size > KMALLOC_MAX_CACHE_SIZE)
- return kmalloc_large_node_noprof(size, flags, node);
+ return __kmalloc_large_node_noprof(size, flags, node);
index = kmalloc_index(size);
- return kmalloc_node_trace_noprof(
+ return __kmalloc_cache_node_noprof(
kmalloc_caches[kmalloc_type(flags, _RET_IP_)][index],
flags, node, size);
}
diff --git a/lib/fortify_kunit.c b/lib/fortify_kunit.c
index 39da5b3bc649..044f409ef856 100644
--- a/lib/fortify_kunit.c
+++ b/lib/fortify_kunit.c
@@ -233,11 +233,6 @@ static void fortify_test_alloc_size_##allocator##_dynamic(struct kunit *test) \
kfree(p)); \
checker(expected_size, \
kmalloc_array_node(alloc_size, 1, gfp, NUMA_NO_NODE), \
- kfree(p)); \
- checker(expected_size, __kmalloc(alloc_size, gfp), \
- kfree(p)); \
- checker(expected_size, \
- __kmalloc_node(alloc_size, gfp, NUMA_NO_NODE), \
kfree(p)); \
\
orig = kmalloc(alloc_size, gfp); \
diff --git a/lib/slub_kunit.c b/lib/slub_kunit.c
index 4ce960438806..e6667a28c014 100644
--- a/lib/slub_kunit.c
+++ b/lib/slub_kunit.c
@@ -140,7 +140,7 @@ static void test_kmalloc_redzone_access(struct kunit *test)
{
struct kmem_cache *s = test_kmem_cache_create("TestSlub_RZ_kmalloc", 32,
SLAB_KMALLOC|SLAB_STORE_USER|SLAB_RED_ZONE);
- u8 *p = kmalloc_trace(s, GFP_KERNEL, 18);
+ u8 *p = __kmalloc_cache_noprof(s, GFP_KERNEL, 18);
kasan_disable_current();
diff --git a/mm/slub.c b/mm/slub.c
index 0809760cf789..95e0a3332c44 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -4053,7 +4053,7 @@ EXPORT_SYMBOL(kmem_cache_alloc_node_noprof);
* directly to the page allocator. We use __GFP_COMP, because we will need to
* know the allocation order to free the pages properly in kfree.
*/
-static void *__kmalloc_large_node(size_t size, gfp_t flags, int node)
+static void *___kmalloc_large_node(size_t size, gfp_t flags, int node)
{
struct folio *folio;
void *ptr = NULL;
@@ -4078,25 +4078,25 @@ static void *__kmalloc_large_node(size_t size, gfp_t flags, int node)
return ptr;
}
-void *kmalloc_large_noprof(size_t size, gfp_t flags)
+void *__kmalloc_large_noprof(size_t size, gfp_t flags)
{
- void *ret = __kmalloc_large_node(size, flags, NUMA_NO_NODE);
+ void *ret = ___kmalloc_large_node(size, flags, NUMA_NO_NODE);
trace_kmalloc(_RET_IP_, ret, size, PAGE_SIZE << get_order(size),
flags, NUMA_NO_NODE);
return ret;
}
-EXPORT_SYMBOL(kmalloc_large_noprof);
+EXPORT_SYMBOL(__kmalloc_large_noprof);
-void *kmalloc_large_node_noprof(size_t size, gfp_t flags, int node)
+void *__kmalloc_large_node_noprof(size_t size, gfp_t flags, int node)
{
- void *ret = __kmalloc_large_node(size, flags, node);
+ void *ret = ___kmalloc_large_node(size, flags, node);
trace_kmalloc(_RET_IP_, ret, size, PAGE_SIZE << get_order(size),
flags, node);
return ret;
}
-EXPORT_SYMBOL(kmalloc_large_node_noprof);
+EXPORT_SYMBOL(__kmalloc_large_node_noprof);
static __always_inline
void *__do_kmalloc_node(size_t size, gfp_t flags, int node,
@@ -4106,7 +4106,7 @@ void *__do_kmalloc_node(size_t size, gfp_t flags, int node,
void *ret;
if (unlikely(size > KMALLOC_MAX_CACHE_SIZE)) {
- ret = __kmalloc_large_node(size, flags, node);
+ ret = __kmalloc_large_node_noprof(size, flags, node);
trace_kmalloc(caller, ret, size,
PAGE_SIZE << get_order(size), flags, node);
return ret;
@@ -4142,7 +4142,7 @@ void *kmalloc_node_track_caller_noprof(size_t size, gfp_t flags,
}
EXPORT_SYMBOL(kmalloc_node_track_caller_noprof);
-void *kmalloc_trace_noprof(struct kmem_cache *s, gfp_t gfpflags, size_t size)
+void *__kmalloc_cache_noprof(struct kmem_cache *s, gfp_t gfpflags, size_t size)
{
void *ret = slab_alloc_node(s, NULL, gfpflags, NUMA_NO_NODE,
_RET_IP_, size);
@@ -4152,10 +4152,10 @@ void *kmalloc_trace_noprof(struct kmem_cache *s, gfp_t gfpflags, size_t size)
ret = kasan_kmalloc(s, ret, size, gfpflags);
return ret;
}
-EXPORT_SYMBOL(kmalloc_trace_noprof);
+EXPORT_SYMBOL(__kmalloc_cache_noprof);
-void *kmalloc_node_trace_noprof(struct kmem_cache *s, gfp_t gfpflags,
- int node, size_t size)
+void *__kmalloc_cache_node_noprof(struct kmem_cache *s, gfp_t gfpflags,
+ int node, size_t size)
{
void *ret = slab_alloc_node(s, NULL, gfpflags, node, _RET_IP_, size);
@@ -4164,7 +4164,7 @@ void *kmalloc_node_trace_noprof(struct kmem_cache *s, gfp_t gfpflags,
ret = kasan_kmalloc(s, ret, size, gfpflags);
return ret;
}
-EXPORT_SYMBOL(kmalloc_node_trace_noprof);
+EXPORT_SYMBOL(__kmalloc_cache_node_noprof);
static noinline void free_to_partial_list(
struct kmem_cache *s, struct slab *slab,
--
2.45.1